CN107655769B - Method and device for testing rock equivalent ultimate shear strength - Google Patents
Method and device for testing rock equivalent ultimate shear strength Download PDFInfo
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Abstract
The invention provides a method and a device for testing rock equivalent ultimate shear strength. The method comprises the following steps: placing the rock equivalent ultimate shear strength testing device in a test pit on the outer side of a rock foundation pit excavated on a rock foundation, and applying a thrust load to the rock foundation through a jack in the rock equivalent ultimate shear strength testing device until the rock foundation is subjected to integral shear failure; recording the maximum jacking force P of the jackmaxThe method comprises the following steps of (1) determining the inner diameter D of an oil cylinder, the diameter a of a part applying a pushing load to a rock mass foundation, the excavation depth h of a foundation pit and fracture angles alpha and beta of two sides of the rock mass foundation; and according to PmaxD, a, h and fracture angles alpha and beta determine rock equivalent ultimate shear strength taus. The testing method can conveniently and accurately measure the rock equivalent ultimate shear strength of the jointed fractured rock mass foundation in the field, provides a basis for the optimal design of the rock embedded foundation of the power transmission line in mountainous areas, is favorable for reducing the construction cost, and realizes energy conservation and emission reduction.
Description
Technical Field
The invention relates to the technical field of transmission line tower foundations, in particular to a method and a device for testing rock equivalent ultimate shear strength.
Background
With the advance of the construction of ultrahigh voltage power grid engineering in China, more and more power transmission lines inevitably approach mountains and mountains or mountainous and hilly lands, the geological conditions of the areas are mostly jointed fractured rock foundations, the bare rocks or the thin soil covering layers are formed, the upper rock layers are in a completely weathered to strongly weathered state, and the power transmission line tower foundation type generally adopts a straight column type, an excavated and expanded bottom type or jar type rock embedded type foundation.
When the rock embedded type foundation design on the strongly weathered joint fractured rock foundation is used for calculating the uplift stability, an important parameter used is rock equivalent ultimate shear strength. Because the existing standard does not relate to the specification of a specific test method of the equivalent ultimate shear strength parameters of the relevant rocks, the value of the equivalent ultimate shear strength of the relevant rocks in a geological survey report of a design unit is usually directly taken according to experience and the lower limit value of the value range in DL/T5219 plus 2014 technical specification of overhead transmission line basic design, so that the safety margin of the rock basic design of the transmission line is large, the size of the foundation is large, the waste of basic body materials is serious, the excavation of a foundation pit is time-consuming and labor-consuming, the progress of engineering construction is restricted, and the economy and the environmental protection are poor.
Disclosure of Invention
In view of the above, the invention provides a method for testing the equivalent ultimate shear strength of rocks, and aims to solve the problem that in the prior art, the economic efficiency and the environmental protection performance of power transmission line engineering construction are poor due to the fact that equivalent ultimate shear strength parameters of jointed fractured rock foundation rocks are difficult to accurately measure. The invention also provides a device for testing the equivalent ultimate shear strength of the joint fractured rock mass foundation rock.
In one aspect, the invention provides a method for testing equivalent ultimate shear strength of a rock, which comprises the following steps: a loading step, namely placing a rock equivalent ultimate shear strength testing device in a test pit on the outer side of a rock foundation pit excavated on a rock foundation, and applying a pushing load to the rock foundation through a jack in the rock equivalent ultimate shear strength testing device until the rock foundation is subjected to integral shear failure; recording parameters, namely recording the maximum jacking force P of the jackmaxThe inner diameter D of an oil cylinder of the jack, the diameter a of a part of the jack applying a pushing load to the rock mass foundation, the excavation depth h of the rock foundation pit and fracture angles alpha and beta on two sides of the rock mass foundation; determining the equivalent ultimate shear strength of the rock according to the maximum jacking force P of the jackmaxDetermining rock equivalent ultimate shear strength tau by using the inner diameter D of the oil cylinder of the jack, the diameter a of a part of the rock mass foundation applied with the pushing load by the jack, the excavation depth h of the rock foundation pit and fracture angles alpha and beta at two sides of the rock mass foundations。
Further, in the method for testing the equivalent ultimate shear strength of the rock, in the step of determining the equivalent ultimate shear strength of the rock, the formula is shown in the specification
Determining the rock equivalent ultimate shear strength taus(ii) a Wherein in the above formula, PmaxThe maximum jacking force of the jack, the inner diameter of an oil cylinder of the jack, the diameter of a part of the jack applying a pushing load on the rock mass foundation, the excavation depth of the rock foundation pit, alpha and beta are fracture angles on two sides of the rock mass foundation respectively tan [ min (alpha, beta) ]]Tangent value being the smaller of α and β, and when tan [ min (α, β)]When the number is equal to 1, the alloy is put into a container,
further, in the method for testing the equivalent ultimate shear strength of rock, before the step of applying a load, the method further comprises: excavating a foundation pit and a test pit, namely excavating a rock foundation pit with a first preset size on a joint fractured rock foundation, excavating a plurality of test pits with a second preset size towards the outer side of the rock foundation pit along the outer edge of the bottom wall of the rock foundation pit, and placing the rock equivalent ultimate shear strength testing device in any one of the test pits.
Further, in the method for testing the equivalent ultimate shear strength of the rock, the first preset size is as follows: length 3m × width 3m × depth 1 m; the second preset size is: 0.3m long by 0.3m wide by 0.52m deep.
Further, in the method for testing the equivalent ultimate shear strength of the rock, in the step of digging the foundation pit and the test pit, before digging the test pit, a plurality of working wells communicated with the test pits are dug towards the inner side of the rock foundation pit along the outer edge of the bottom wall of the rock foundation pit.
Further, in the method for testing the equivalent ultimate shear strength of the rock, in the step of digging the foundation pit and the test pit, the test pits and the working wells are dug by taking the central points of the outer edge of the bottom wall of the foundation pit of the rock as centers.
Further, in the method for testing rock equivalent ultimate shear strength, in the step of determining rock equivalent ultimate shear strength, the rock equivalent ultimate shear strength τ tested in each test pit by the rock equivalent ultimate shear strength testing device is determinedsIs determined as the rock equivalent ultimate shear strength tausIs a representative value of (a).
On the other hand, the invention also provides a device for testing the equivalent ultimate shear strength of the rock, which comprises: a loading frame arranged in the test pit and used for placing the jack; the first bearing plate is arranged in the test pit, the top end of the first bearing plate is in contact with the rock mass foundation at the top of the test pit, and the bottom of the first bearing plate is connected with the loading frame and used for receiving the push-up load applied by the jack; and the jack is arranged in the loading frame and is used for applying pushing load to the rock mass foundation.
Further, in the apparatus for testing rock equivalent ultimate shear strength, the loading frame includes: the second bearing plate is in contact with a rock mass foundation at the bottom of the test pit; and the positioning rods are arranged on the second bearing plate and connected with the first bearing plate.
Furthermore, in the device for testing the equivalent ultimate shear strength of the rock, a positioning ring is further arranged on the second bearing plate, and the bottom of the jack is connected with the positioning ring.
Compared with the prior art that the lower limit value of the rock equivalent ultimate shear strength is directly taken according to the value range in DL/T5219-; the invention records the maximum jacking force P of jack in the test processmaxThe method comprises the following steps of measuring the maximum jacking force P of a jack, the inner diameter D of an oil cylinder of the jack, the diameter a of a part of a rock foundation to which the jack applies a pushing load, the excavation depth h of a rock foundation pit, fracture angles alpha and beta of two sides of the rock foundation pit, and measuring the maximum jacking force P of the jackmaxDetermining rock equivalent ultimate shear strength tau by using the inner diameter D of the oil cylinder of the jack, the diameter a of a part of the jack applying a pushing load to the rock mass foundation, the excavation depth h of the rock foundation pit and fracture angles alpha and beta on two sides of the rock mass foundations。
Furthermore, the jack pushes the first bearing plate to apply an upper pushing load to the joint fractured rock mass foundation at the upper part, meanwhile, the counter force is diffused to the joint fractured rock mass foundation at the lower part through the second bearing plate of the loading frame, and the load is continuously applied to the joint fractured rock mass foundation to cause the integral shearing failure of the rock, so that the equivalent ultimate shearing strength parameters of the rock can be measured, and the testing device has a simple structure and is convenient to manufacture; the important design parameter of rock equivalent ultimate shear strength of the strongly weathered jointed fractured rock mass foundation can be conveniently and accurately measured in situ in the field, so that the blindness and randomness of the surveying work are reduced, an important reference basis is provided for the optimization design of the rock embedded type foundation of the power transmission line in the mountainous area, the construction cost is reduced, and the energy conservation and emission reduction are realized.
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Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:
FIG. 1 is a flow chart of a method for testing rock equivalent ultimate shear strength provided by an embodiment of the invention;
fig. 2 is a schematic top view structure diagram of a rock foundation pit and a test pit in the method for testing rock equivalent ultimate shear strength according to the embodiment of the present invention;
FIG. 3 is a schematic diagram of a test state in the rock equivalent ultimate shear strength test method provided by the embodiment of the invention;
fig. 4 is a front view of a first bearing plate in the rock equivalent ultimate shear strength testing apparatus provided in the embodiment of the present invention;
fig. 5 is a top view of a first bearing plate in the device for testing rock equivalent ultimate shear strength according to the embodiment of the present invention;
FIG. 6 is a front view of a loading frame in the rock equivalent ultimate shear strength testing apparatus provided in the embodiment of the present invention;
fig. 7 is a top view of a loading frame in the rock equivalent ultimate shear strength testing apparatus provided in the embodiment of the present invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
The method comprises the following steps:
fig. 1 is a flow chart of a method for testing equivalent ultimate shear strength of rock mass foundation rocks according to an embodiment of the invention. The method comprises the following steps:
step S1, excavating a rock foundation pit with a first preset size on the rock foundation, excavating a plurality of test pits with a second preset size towards the outer side of the foundation pit along the outer edge of the bottom wall of the rock foundation pit, and placing the rock equivalent ultimate shear strength testing device in any one of the test pits. In this embodiment, the jointed fractured rock foundation is taken as an example, the size of the rock foundation pit 1 may be 3m long × 3m wide × 1m deep, and the size of the test pit may be 0.3m long × 0.3m wide × 0.52m deep.
It should be noted that the depth of the test pit 2 is relative to the rock foundation of the plane of the bottom wall of the rock foundation pit 1 as a reference line.
Referring to fig. 2, before excavating the test pits, a plurality of working wells 3 communicated with the test pits 2 need to be excavated towards the inner side of the foundation pit along the outer edge of the bottom wall of the foundation pit, and the size of the working wells can be selected according to actual conditions, for example, the size of the working wells 3 can also be 0.3m long by 0.3m wide by 0.52m deep. It should be noted that the depths of the test pit 2 and the working well 3 are taken relative to the rock foundation of the plane of the bottom wall of the rock foundation pit 1 as a reference line.
Preferably, each test pit 2 and each working well 3 are excavated centering on each central point of the outer edge of the bottom wall of the foundation pit. During specific implementation, the upright rock foundation pit 1 is excavated manually by tools such as a foreign pick, a shovel, an air pick and the like, then four working wells 3 and four test pits 2 are excavated in sequence at the periphery center of the edge of the bottom wall of the rock foundation pit 1, the pit wall and the isolated rock blocks protruding from the pit bottom of the test pit 2 are polished to be flat, and the bottom of the test pit 2 is strictly leveled by fine sand.
And S2, placing the rock equivalent ultimate shear strength testing device in a test pit on the outer side of a rock foundation pit excavated on the rock foundation, and applying a pushing load to the rock foundation through a jack in the rock equivalent ultimate shear strength testing device until the rock foundation is subjected to integral shear failure.
Step S3, recording the maximum jacking force P of the jackmaxThe method comprises the following steps of firstly, determining the inner diameter D of an oil cylinder of a jack, determining the diameter a of a part of a rock foundation to which the jack applies a pushing load, excavating depth h of a rock foundation pit, and fracture angles alpha and beta of two sides of the rock foundation.
Referring to fig. 3, the maximum jacking force P of the jack can be read by a pressure gauge of a pressure supply device connected with the jackmaxAnd measuring fracture angles alpha and beta of the left side and the right side of the strongly weathered joint fractured rock foundation according to the protractor for the crack propagation outer enveloping surface.
Step S3, according to the maximum jacking force P of the jackmaxDetermining rock equivalent ultimate shear strength tau by using the inner diameter D of the oil cylinder of the jack, the diameter a of a part of the jack applying a pushing load to the rock mass foundation, the excavation depth h of the rock foundation pit and fracture angles alpha and beta on two sides of the rock mass foundations。
Specifically, according to the formula
Determination of rock equivalent ultimate shear strength taus. In the formula, PmaxThe maximum jacking force of the jack is expressed in MPa; a is the diameter of the part of the jack applying the pushing load to the rock foundation, and the unit is m; h is the excavation depth of the rock foundation pit, and the unit is m; d is the inner diameter of the oil cylinder of the jack, and the unit is mm. tan [ min (alpha, beta)]Is the tangent of the smaller of a and β. When the smaller of α and β is 45 °, or when both α and β are 45 °, it is considered that
That is, during the development of shear failure microcracks in the joint-fractured rock mass foundation, α and β tend to be unequal whenWhen the minimum value of the measured alpha or beta is 45 degrees, the rock equivalent ultimate shear strength parameter tau is consideredsIs equal to the rock ultimate shear strength parameter tau. When the rock stratum in the rock mass foundation is subjected to homogeneous fracture, alpha and beta are considered to be equal, and similarly, when the measured alpha and beta angles are 45 degrees, the rock equivalent ultimate shear strength parameter tau is considered to besIs equal to the rock ultimate shear strength parameter tau. In this example, a may be 0.3m or h may be 1m, and this is obtained
Preferably, the rock equivalent ultimate shear strength tau is tested in each test pit by a rock equivalent ultimate shear strength testing devicesIs determined as the rock equivalent ultimate shear strength tausIs a representative value of (a).
With reference to fig. 2 and 3, testing tests of the rock equivalent ultimate shear strength parameters are respectively performed in the four test pits 2, and the minimum value is taken as the representative value of the rock equivalent ultimate shear strength, so that the test result is more accurate and reliable, and data support can be better provided for the optimal design of the rock embedded type foundation of the power transmission line in the mountainous area.
Taking four test pits as an example, the test procedure of this example is as follows: the rock equivalent ultimate shear strength testing device is placed in one of the test pits, the jack applies load to the jack according to proper load grades, the pressure gauge of the pressure supply device monitors the oil pressure of the jack constantly, the jack applies a thrust load to the upper strongly weathered jointed fractured rock foundation, and the counter force of the thrust load is diffused to the lower strongly weathered jointed fractured rock foundation. When the strongly weathered jointed fractured rock foundation at the upper part cannot bear the push-up load applied by the jack, the shear failure micro-cracks begin to appear in the strongly weathered jointed fractured rock foundation; with the continuous increase of the push-up load, the shear failure microcracks in the strongly weathered joint fractured rock mass foundation begin to develop and expand continuously and are connected and communicated until the push-up load cannot be maintained, and the strongly weathered joint fractured rock mass foundation is subjected to integral rock shear failure. Recording the maximum reading P of the oil pressure gauge in the rock shearing failure processmaxAndmeasuring fracture angles alpha and beta on the left side and the right side of the strongly weathered jointed fractured rock foundation according to the outer enveloping surface of the fracture expansion, and calculating the fracture angles alpha and beta according to a formula
Calculating the rock ultimate shear strength parameter tau of the strongly weathered joint fractured rock mass foundation, and further according to a formula
Calculating the equivalent ultimate shear strength parameter tau of the rocks. By analogy, the same test process is respectively carried out in other three test pits, and finally the rock equivalent ultimate shear strength parameter tau in the four tests is takensThe minimum value of (a) is used as a representative value of rock equivalent ultimate shear strength.
The above obviously shows that the jack in the rock equivalent ultimate shear strength testing device applies the pushing load to the rock mass foundation until the rock mass foundation is subjected to integral shear failure. Recording the maximum jacking force P of jack in the processmaxThe method comprises the following steps of firstly, determining the maximum jacking force P of a jack, determining the inner diameter D of an oil cylinder of the jack, determining the diameter a of a part of a rock foundation to which the jack applies a pushing load, the excavation depth h of a rock foundation pit and fracture angles alpha and beta on two sides of the rock foundation, and determining the maximum jacking force P of the jackmaxDetermining rock equivalent ultimate shear strength tau by using the inner diameter D of the oil cylinder of the jack, the diameter a of a part of the jack applying a pushing load to the rock mass foundation, the excavation depth h of the rock foundation pit and fracture angles alpha and beta on two sides of the rock mass foundations. The important design parameter of rock equivalent ultimate shear strength of the strongly weathered jointed fractured rock mass foundation can be conveniently and accurately measured in situ in the field, so that the blindness and randomness of the surveying work are reduced, an important reference basis is provided for the optimization design of the rock embedded type foundation of the power transmission line in the mountainous area, the construction cost is reduced, and the energy conservation and emission reduction are realized.
The embodiment of the device is as follows:
referring to fig. 4 to 7, the invention also provides a device for testing the equivalent ultimate shear strength of the jointed and fractured rock mass foundation rock, which comprises: a loading frame 4, a first bearing plate 5 and a jack 6; wherein, in experimental hole 2 is all arranged in to loading frame 4 and first bearing plate 5 to, the top of first bearing plate 5 contacts with the rock mass ground 8 at experimental hole 2 top, and the bottom of first bearing plate 5 is connected with loading frame 4.
Specifically, the jack 6 may be a 100T oil jack with a cylinder bore of 140 mm. In specific implementation, the jack 6 can be connected with a manual pump, and oil is supplied and pressurized to an oil path of the jack through the manual pump. By fixing the jack 6 in the loading frame and applying a push load to the first bearing plate 5, the push load is transmitted to the rock mass foundation 8 above.
The first bearing plate 5 may be made of a Q345 steel plate, and may have a shape of: upper portion is circular plate, lower part is square board, circular plate and square board integrated into one piece to, the structural a plurality of first bolt holes 51 of having seted up of square platelike of lower part, preferably, the quantity of first bolt hole 51 is 4 and 4 first bolt holes 51 two double-column symmetry arrange on the square board of first bearing plate 5. Wherein the diameter of the circular plate is 300mm, and the height of the circular plate is 50 mm; the side length of the square plate is 300mm, and the height of the square plate is 20 mm; the diameter of the 4 bolt holes is 25 mm.
The loading frame 4 may include: a second bearing plate 41 which is in contact with the rock mass foundation 8 at the bottom of the test pit; and a plurality of positioning rods 42 provided on the second pressure receiving plate 41 and connected to the first pressure receiving plate 5. The second bearing plate 41 may be a solid steel plate of Q345, and may be a square plate with a side length of 300mm and a height of 70 mm. A plurality of second bolt holes 42, for example, four symmetrically distributed second bolt holes 42, are formed in the second bearing plate 41, and a plurality of positioning rods, for example, 4 positioning screws having a diameter of 20mm, a total length of 520mm, an exposed length of 450mm, and a material of Q235 steel, are disposed on the second bearing plate 41. First ends (lower ends shown in fig. 6) of the positioning rods can penetrate through the corresponding second bolt holes 42 and then are fastened to the second bearing plate 41, and second ends (upper ends shown in fig. 6) of the positioning rods can penetrate through the corresponding first bolt holes 51 and fastened to the first bearing plate 5, so that the first bearing plate 5 can be accurately positioned and stably fixed.
Preferably, the second bearing plate 41 is further provided with a positioning ring 7, and the bottom of the jack 6 is connected with the positioning ring 7. The second bearing plate 41 and the bottom of the positioning ring 7 can be welded, and the positioning ring 7 can be a disc-shaped structure made of Q235 steel with an outer diameter of 240mm, an inner diameter of 230mm and a height of 30 mm. During specific implementation, after the jack 6 is fixed on the positioning ring 7, the positioning rod 42 is tightly connected with the first bearing plate 5, and the positioning plate 7 can prevent the jack 6 from deviating from the action direction when pushing load is applied to the rock mass foundation 8.
The specific working process of this embodiment may refer to the above method embodiment, and details are not described here.
Obviously, the first bearing plate is pushed by the jack to apply an upper pushing load to the joint fractured rock mass foundation at the upper part, meanwhile, the counter force is diffused to the joint fractured rock mass foundation at the lower part through the second bearing plate of the loading frame, the load is continuously applied to the joint fractured rock mass foundation to generate rock integral shearing damage, and the equivalent ultimate shearing strength parameters of the rock can be measured. On one hand, the structure is simple and the manufacture is convenient; on the other hand, the method can conveniently and accurately measure the important design parameter of the rock equivalent ultimate shear strength of the strongly weathered jointed fractured rock mass foundation in the field, provides a reference basis for the optimal design of the rock embedded foundation of the power transmission line in the mountainous area, and reduces the construction cost.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (8)
1. A test method for rock equivalent ultimate shear strength is characterized by comprising the following steps:
excavating a foundation pit and a test foundation pit, namely excavating a rock foundation pit with a first preset size on a rock foundation, excavating a plurality of test pits with a second preset size towards the outer side of the foundation pit along the outer edge of the bottom wall of the rock foundation pit, and placing a rock equivalent ultimate shear strength testing device in any one test pit;
a loading step, namely placing a rock equivalent ultimate shear strength testing device in a test pit on the outer side of a rock foundation pit excavated on a rock foundation, and applying a pushing load to the rock foundation through a jack in the rock equivalent ultimate shear strength testing device until the rock foundation is subjected to integral shear failure;
recording parameters, namely recording the maximum jacking force P of the jackmaxThe inner diameter D of an oil cylinder of the jack, the diameter a of a part of the jack applying a pushing load to the rock mass foundation, the excavation depth h of the rock foundation pit and fracture angles alpha and beta on two sides of the rock mass foundation;
determining the equivalent ultimate shear strength of the rock according to the maximum jacking force P of the jackmaxDetermining rock equivalent ultimate shear strength tau through the inner diameter D of the oil cylinder of the jack, the diameter a of a part of the jack applying the pushing load to the rock mass foundation, the excavation depth h of the rock foundation pit and fracture angles alpha and beta at two sides of the rock mass foundations(ii) a According to the formula
Determining the rock equivalent ultimate shear strength tausWherein alpha and beta are fracture angle, tan [ min (alpha, beta) of two sides of the rock foundation respectively]Tangent value being the smaller of α and β, and when tan [ min (α, β)]When the number is equal to 1, the alloy is put into a container,
2. the method for testing equivalent ultimate shear strength of rock according to claim 1, wherein the first preset dimension is: length 3m × width 3m × depth 1 m; the second preset size is: 0.3m long by 0.3m wide by 0.52m deep.
3. The method for testing ultimate shear strength of a rock according to claim 1, wherein in the excavating a foundation pit and a test pit, before excavating the test pit, a plurality of working wells communicated with the test pits are excavated toward the inner side of the foundation pit along the outer edge of the bottom wall of the foundation pit.
4. The method for testing ultimate shear strength of a rock according to claim 3, wherein in the excavation of the foundation pit and the test pit, each of the test pits and each of the working wells are excavated centering on each center point of the outer edge of the bottom wall of the foundation pit.
5. The method for testing rock equivalent ultimate shear strength according to claim 4, wherein in the rock equivalent ultimate shear strength determining step, the rock equivalent ultimate shear strength τ of the rock equivalent ultimate shear strength test device tested in each of the test pits is determinedsIs determined as the rock equivalent ultimate shear strength tausIs a representative value of (a).
6. A test apparatus used in the rock equivalent ultimate shear strength test method according to any one of claims 1 to 5, comprising:
a loading frame (4) arranged in the test pit (2) and used for placing a jack (6);
the first bearing plate (5) is arranged in the test pit (2), the top end of the first bearing plate is in contact with the rock mass foundation at the top of the test pit (2), and the bottom of the first bearing plate is connected with the loading frame (4) and used for receiving the push-up load applied by the jack (6);
and the jack (6) is arranged in the loading frame (4) and is used for applying pushing load to the rock mass foundation.
7. The test device of rock equivalent ultimate shear strength according to claim 6, characterized in that the loading frame (4) comprises:
a second bearing plate (41) which is in contact with a rock mass foundation at the bottom of the test pit;
and a plurality of positioning rods (42) which are arranged on the second bearing plate (41) and connected with the first bearing plate (5).
8. The device for testing the equivalent ultimate shear strength of rock according to claim 7, wherein a positioning ring (7) is further arranged on the second bearing plate (41), and the bottom of the jack (6) is connected with the positioning ring (7).
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| CN201710662792.2A CN107655769B (en) | 2017-08-04 | 2017-08-04 | Method and device for testing rock equivalent ultimate shear strength |
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